Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 3, 2014 at 05:15 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update December 1, 2014)] [Cycle 24 progress (last update December 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update December 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update December 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update December 3, 2014)]

[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated November 22, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on December 2. Solar wind speed at SOHO ranged between 446 and 603 km/s under the influence of weak CME effects.

Solar flux at 20h UTC on 2.8 GHz was 167.7 (increasing 32.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 151.6 - the highest since May 2, 2014). The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.4). Three hour interval K indices: 33313231 (planetary), 23323232 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 282) and 10 active regions using 1K resolution (SN: 178) SDO images on the visible solar disk.

Region 12217 [S16W51] developed slowly with a magnetic delta forming. C and minor M class flares are possible.
Region 12218 [N17W36] was quiet and stable.
Region 12221 [N06W11] developed slowly and has polarity intermixing after new flux emerged.
Region 12222 [S19W11] lost spots and remains capable of M class flare production.
Region 12224 [S24W22] was quiet and stable.
Region 12225 [S15E34] decayed slowly and quietly.
Region 12226 [S19W33] developed slowly and could produce further C class flares.
New region 12227 [S03E74] rotated into view.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4042 [S03W26] was quiet and stable.
New region S4047 [N09E58] emerged with a penumbra spot.
New region S4048 [N08E65] rotated into view.
New region S4049 [S09E12] was observed with penumbra spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.2 04:29   12222  
C2.1 05:46 S24E02 12222  
C4.1 13:52   12226  
C6.5 15:55   12222  
C3.9 17:35   12226  
C2.4 20:34   12224  
C2.7 21:30      
C3.0 22:30   12222  

Coronal mass ejections (CMEs)

November 30 - December 2: No obviously Earth directed CMEs were observed in LASCO imagery.

Coronal holes

[Coronal hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago]

No obvious coronal holes are currently in or near Earth facing positions.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on December 3-5.

Coronal holes (1) Coronal mass ejection (2) M and X class flares (3)
     

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.

Active solar regions

(Click on image for 2K resolution) Compare to the previous day's image. 0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.

Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.

Active region Date numbered
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12216 2014.11.19
2014.11.20
1     S14W90 0090 HSX     rotated out of view
12217 2014.11.22
2014.11.23
9 23 12 S16W51 0120 DAI DAC beta-gamma-delta
S4020 2014.11.23       N15W44         plage
12218 2014.11.23 1 6 2 N16W36 0170 HSX CAO

 

12219 2014.11.24 2     N03W90 0120 HSX     plage
12220 2014.11.24       S16W83         plage
12221 2014.11.25
2014.11.26
8 36 18 N06W11 0070 CAO DAI beta-gamma
12222 2014.11.26 27 47 20 S19W10 0620 EKI EKC beta-gamma

area: 0860

12224 2014.11.26
2014.11.28
  3   S24W27 0004   BXO location: S24W22
12223 2014.11.26
2014.11.27
      N15W80         plage
S4037 2014.11.26       N12W54           plage
12226 2014.11.27
2014.12.01
4 24 17 S19W36 0040 CAO DAI beta-gamma

area: 0100

S4041 2014.11.27       N26W47           plage
S4042 2014.11.27   5 2 S03W26 0012   BXO  
12225 2014.11.29
2014.11.30
3 9 4 S17E30 0010 BXO BXO location: S15E34

area: 0020

S4045 2014.11.30       N24W35            
12227 2014.12.02 1 4 1 S03E71 0060 HSX CSO   location: S03E74

area: 0190

S4047 2014.12.02   1 1 N09E58 0004   AXX    
S4048 2014.12.02   1 1 N08E65 0003   AXX    
S4049 2014.12.02   3   S09E12 0005   AXX    
Total spot count: 56 162 78  
Sunspot number: 146 282 178  (total spot count + 10 * number of spotted regions)
Weighted SN: 101 197 113  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 88 99 98 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1)
(likely solar max)
7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 (79.1 projected, -1.6) 6.72
2014.07 137.4 141.8 72.5 (77.5 projected, -1.6) 4.50
2014.08 124.7 127.9 74.7 (75.1 projected, -3.0) 7.71
2014.09 146.6 148.1 87.6 (71.9 projected, -3.2) 9.78
2014.10 153.4 152.9 60.6 (69.5 projected, -2.4) 8.96
2014.11 154.8   70.1 (67.7 projected, -1.8) 8.9
2014.12 167.9 (1)   9.9 (2A) / 154 (2B) / 92.1 (2C) (66.0 projected, -1.7) (9.7)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official WDC-SILSO international sunspot number is typically 30-50% lower. 2B) Boulder SN current month average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international GFZ Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.